fix: preserve in-memory dev output

[ScriptedAlchemy]

Summary

• stop forcing dev.writeToDisk: true
• preserve Rsbuild's in-memory development default and explicit writeToDisk: false
• align the route-watch E2E with in-memory route additions: require the route to become available, without requiring a disk restart marker
• add a patch changeset

Root cause

The plugin unconditionally overrode Rsbuild's development output setting, forcing every dev compilation to write to disk. The existing route-add E2E also treated a disk restart marker as part of the contract, although in-memory compilation can expose the new route without that signal.

Verification

• pnpm exec rstest run -c ./rstest.config.ts tests/index.test.ts tests/features.test.ts (red before fix, 42 passed after, including explicit writeToDisk: true preservation)
• pnpm exec rstest run -c ./rstest.config.ts tests/dev-runtime.integration.test.ts (2 passed)
• pnpm test:core (481 passed)
• pnpm build
• pnpm --filter default-template exec playwright test tests/e2e/dev-route-watch.test.ts --workers=1 --repeat-each=3 (3 passed)
• Prettier checks on all changed files
• git diff --check

Forward-ports the writeToDisk portion of #86 without its unrelated optimization changes.

[pkg-pr-new]

Open in StackBlitz

pnpm add https://pkg.pr.new/rsbuild-plugin-react-router@4ae8053

commit: 4ae8053

[coderabbitai]

📝 Walkthrough

Walkthrough

The plugin no longer sets dev.writeToDisk to true when modifying the Rsbuild configuration. Tests now expect the development configuration to keep writeToDisk disabled by default. The route-watch E2E test no longer checks for a restart after the initial route addition, and a patch changeset documents the updated behavior.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly summarizes the main change: preserving in-memory dev output by not forcing disk writes.
Description check	✅ Passed	The description is directly related to the changeset and accurately explains the behavior change and verification.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch codex/write-to-disk-false

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[github-actions]

Benchmark Results

Compared PR head 4ae8053 against base 27ab2ce.

Reading benchmark confidence

Raw deltas are always shown. The signal label only indicates whether the observed median delta is larger than a robust run-to-run noise band; it does not erase or replace the measurement.

The noise band is the larger of 2% or two combined robust standard deviations estimated from each side's relative median absolute deviation (rMAD). Fewer than three finite samples is reported as insufficient data. An inconclusive result should be rerun or investigated from the uploaded raw samples before drawing a performance conclusion.

Benchmark	Runs	Base total	Head total	Delta	Base rMAD	Head rMAD	Noise band	Signal
large-355-ssr-esm (build)	3	8.19s	8.28s	+1.1%	0.1%	0.8%	±2.4%	⚪ inconclusive
synthetic-1024-ssr-esm (build)	3	3.90s	3.81s	-2.3%	0.4%	0.2%	±2.0%	🟢 improvement
synthetic-1024-ssr-esm-split (build)	3	5.22s	5.15s	-1.3%	0.4%	0.4%	±2.0%	⚪ inconclusive
synthetic-256-sourcemaps (build)	5	2.20s	2.18s	-0.7%	0.5%	0.7%	±2.5%	⚪ inconclusive
synthetic-256-ssr-esm (build)	5	2.06s	2.02s	-2.0%	1.1%	1.5%	±5.5%	⚪ inconclusive
synthetic-256-ssr-esm-split (build)	5	2.45s	2.42s	-1.4%	0.4%	0.4%	±2.0%	⚪ inconclusive
synthetic-48-ssr-esm (build)	5	1.33s	1.32s	-0.6%	0.6%	0.9%	±3.2%	⚪ inconclusive
large-355-ssr-esm (dev)	3	15.38s	13.34s	-13.2%	1.6%	0.6%	±5.1%	🟢 improvement
synthetic-1024-ssr-esm (dev)	3	4.47s	4.23s	-5.3%	1.0%	0.7%	±3.6%	🟢 improvement
synthetic-1024-ssr-esm-split (dev)	3	4.44s	4.23s	-4.8%	0.6%	0.8%	±3.0%	🟢 improvement
synthetic-256-sourcemaps (dev)	5	2.06s	1.92s	-6.6%	0.4%	0.8%	±2.6%	🟢 improvement
synthetic-256-ssr-esm (dev)	5	1.83s	1.72s	-6.1%	1.0%	1.1%	±4.4%	🟢 improvement
synthetic-256-ssr-esm-split (dev)	5	1.82s	1.73s	-4.8%	0.6%	0.7%	±2.7%	🟢 improvement
synthetic-48-ssr-esm (dev)	5	0.93s	0.89s	-5.2%	0.4%	0.6%	±2.2%	🟢 improvement
complex app (cold)	3	112.59s	118.84s	+5.6%	0.6%	0.1%	±2.0%	🔴 regression
complex app (dev)	3	99.43s	102.11s	+2.7%	0.8%	1.9%	±5.9%	⚪ inconclusive
complex app (warm)	3	77.44s	86.81s	+12.1%	0.0%	3.9%	±11.4%	🔴 regression

Dev Rollup

Group	Fixtures	Base total	Head total	Delta	Base ready	Head ready	Ready delta	Base routes	Head routes	Route delta	Base update/HMR	Head update/HMR	Update delta	Speedup
All dev fixtures	7	30.93s	28.06s	-9.3%	18.57s	17.60s	-5.2%	3.81s	3.73s	-2.1%	2.69s	2.47s	-8.0%	1.10x
Large app	1	15.38s	13.34s	-13.2%	7.82s	7.34s	-6.2%	1.83s	1.85s	+0.8%	1.60s	1.41s	-11.8%	1.15x
Standard fixtures	6	15.56s	14.72s	-5.4%	10.75s	10.26s	-4.6%	1.98s	1.88s	-4.9%	1.09s	1.06s	-2.5%	1.06x

Production Build Benchmarks

Rendered 7 production build benchmarks.

Benchmark	Runs	Base total	Head total	Delta	Head mean	Head p95	Speedup	Head RSS p95
large-355-ssr-esm	3	8.19s	8.28s	+1.1%	8.26s	8.35s	0.99x	1497 MB
synthetic-1024-ssr-esm	3	3.90s	3.81s	-2.3%	3.84s	3.89s	1.02x	644 MB
synthetic-1024-ssr-esm-split	3	5.22s	5.15s	-1.3%	5.16s	5.20s	1.01x	804 MB
synthetic-256-sourcemaps	5	2.20s	2.18s	-0.7%	2.19s	2.21s	1.01x	447 MB
synthetic-256-ssr-esm	5	2.06s	2.02s	-2.0%	2.03s	2.07s	1.02x	407 MB
synthetic-256-ssr-esm-split	5	2.45s	2.42s	-1.4%	2.43s	2.46s	1.01x	448 MB
synthetic-48-ssr-esm	5	1.33s	1.32s	-0.6%	1.32s	1.34s	1.01x	288 MB

ci-small+ci-large Dev Fixture Summary

Rendered 7 dev benchmark fixtures from the ci-small+ci-large profile.

Benchmark	Runs	Base total	Head total	Delta	Base ready	Head ready	Base routes	Head routes	Base update/HMR	Head update/HMR	Update delta	Head mean	Head p95	Speedup	Head RSS p95
large-355-ssr-esm	3	15.38s	13.34s	-13.2%	7.82s	7.34s	1.83s	1.85s	1.60s	1.41s	-11.8%	13.33s	13.42s	1.15x	-
synthetic-1024-ssr-esm	3	4.47s	4.23s	-5.3%	3.04s	2.93s	0.57s	0.52s	0.33s	0.30s	-7.3%	4.22s	4.26s	1.06x	-
synthetic-1024-ssr-esm-split	3	4.44s	4.23s	-4.8%	3.05s	2.92s	0.56s	0.52s	0.33s	0.33s	-0.0%	4.23s	4.26s	1.05x	-
synthetic-256-sourcemaps	5	2.06s	1.92s	-6.6%	1.48s	1.39s	0.25s	0.22s	0.13s	0.13s	-0.4%	1.92s	1.96s	1.07x	-
synthetic-256-ssr-esm	5	1.83s	1.72s	-6.1%	1.28s	1.19s	0.25s	0.24s	0.13s	0.13s	-2.3%	1.72s	1.75s	1.07x	-
synthetic-256-ssr-esm-split	5	1.82s	1.73s	-4.8%	1.26s	1.21s	0.23s	0.25s	0.13s	0.13s	-0.1%	1.73s	1.75s	1.05x	-
synthetic-48-ssr-esm	5	0.93s	0.89s	-5.2%	0.65s	0.62s	0.12s	0.13s	0.05s	0.05s	+0.5%	0.89s	0.91s	1.06x	-

large-355-ssr-esm Plugin Operations

Environment	Operation	Count	Base total	Head total	Delta	Head wall	Head max	Reports
web	route:module	1071	1035.5ms	1059.2ms	+2.3%	1059.2ms	18.3ms	6
node	route:module	1071	515.1ms	502.6ms	-2.4%	502.6ms	11.8ms	6
web	route:client-entry	1071	276.5ms	251.4ms	-9.1%	251.4ms	5.2ms	6
node	manifest:transform	3	71.6ms	63.7ms	-11.0%	63.7ms	23.5ms	3
web	manifest:stage	6	12.0ms	11.5ms	-4.2%	11.5ms	4.7ms	6
web	manifest:transform	3	0.2ms	0.3ms	+50.0%	0.3ms	0.1ms	3

synthetic-1024-ssr-esm Plugin Operations

Environment	Operation	Count	Base total	Head total	Delta	Head wall	Head max	Reports
web	route:module	3078	1186.2ms	1198.8ms	+1.1%	1198.8ms	10.4ms	6
node	route:module	3078	552.6ms	588.3ms	+6.5%	588.3ms	5.1ms	6
web	route:client-entry	3078	360.3ms	388.2ms	+7.7%	388.2ms	6.5ms	6
node	manifest:transform	3	118.4ms	124.9ms	+5.5%	124.9ms	47.6ms	3
web	manifest:stage	6	40.6ms	31.0ms	-23.6%	31.0ms	9.0ms	6
node	module:client-only-stub	3	35.3ms	139.1ms	+294.1%	139.1ms	84.1ms	3
web	manifest:transform	3	0.3ms	0.3ms	0.0%	0.3ms	0.1ms	3

synthetic-1024-ssr-esm-split Plugin Operations

Environment	Operation	Count	Base total	Head total	Delta	Head wall	Head max	Reports
web	route:module	3078	1209.5ms	1198.5ms	-0.9%	1198.5ms	16.5ms	6
node	route:module	3078	588.1ms	550.9ms	-6.3%	550.9ms	6.0ms	6
node	module:client-only-stub	3	367.4ms	49.6ms	-86.5%	49.6ms	19.0ms	3
web	route:client-entry	3078	356.9ms	358.5ms	+0.4%	358.5ms	6.2ms	6
node	manifest:transform	3	120.7ms	120.4ms	-0.2%	120.4ms	42.1ms	3
web	manifest:stage	6	42.7ms	29.5ms	-30.9%	29.5ms	7.2ms	6
web	manifest:transform	3	0.3ms	0.3ms	0.0%	0.3ms	0.1ms	3

synthetic-256-sourcemaps Plugin Operations

Environment	Operation	Count	Base total	Head total	Delta	Head wall	Head max	Reports
web	route:module	1290	717.9ms	709.5ms	-1.2%	709.5ms	10.8ms	10
node	route:module	1290	299.8ms	306.3ms	+2.2%	306.3ms	5.4ms	10
web	route:client-entry	1290	198.4ms	197.8ms	-0.3%	197.8ms	4.7ms	10
node	module:client-only-stub	5	90.0ms	59.1ms	-34.3%	59.1ms	17.7ms	5
node	manifest:transform	5	69.5ms	88.4ms	+27.2%	88.4ms	20.2ms	5
web	manifest:stage	11	16.5ms	13.2ms	-20.0%	13.2ms	2.9ms	11
web	manifest:transform	5	0.5ms	0.5ms	0.0%	0.5ms	0.1ms	5

synthetic-256-ssr-esm Plugin Operations

Environment	Operation	Count	Base total	Head total	Delta	Head wall	Head max	Reports
web	route:module	1291	709.8ms	717.1ms	+1.0%	717.1ms	18.8ms	11
node	route:module	1290	269.3ms	277.2ms	+2.9%	277.2ms	4.2ms	10
web	route:client-entry	1291	198.0ms	209.7ms	+5.9%	209.7ms	5.3ms	11
node	manifest:transform	5	82.9ms	82.9ms	0.0%	82.9ms	21.8ms	5
node	module:client-only-stub	5	27.4ms	63.7ms	+132.5%	63.7ms	22.7ms	5
web	manifest:stage	11	14.7ms	10.8ms	-26.5%	10.8ms	1.3ms	11
web	manifest:transform	5	0.5ms	0.5ms	0.0%	0.5ms	0.1ms	5

synthetic-256-ssr-esm-split Plugin Operations

Environment	Operation	Count	Base total	Head total	Delta	Head wall	Head max	Reports
web	route:module	1290	684.9ms	706.2ms	+3.1%	706.2ms	19.5ms	10
node	route:module	1290	275.4ms	270.4ms	-1.8%	270.4ms	4.6ms	10
web	route:client-entry	1290	186.4ms	201.7ms	+8.2%	201.7ms	4.8ms	10
node	manifest:transform	5	112.3ms	97.3ms	-13.4%	97.3ms	22.9ms	5
node	module:client-only-stub	5	58.0ms	31.0ms	-46.6%	31.0ms	13.3ms	5
web	manifest:stage	10	14.0ms	10.2ms	-27.1%	10.2ms	1.5ms	10
web	manifest:transform	5	0.5ms	0.5ms	0.0%	0.5ms	0.1ms	5

synthetic-48-ssr-esm Plugin Operations

Environment	Operation	Count	Base total	Head total	Delta	Head wall	Head max	Reports
web	route:module	250	237.9ms	199.8ms	-16.0%	199.8ms	10.0ms	10
node	route:module	250	83.5ms	81.5ms	-2.4%	81.5ms	0.8ms	10
web	route:client-entry	250	59.4ms	52.3ms	-12.0%	52.3ms	3.4ms	10
node	module:client-only-stub	5	44.7ms	37.4ms	-16.3%	37.4ms	10.8ms	5
node	manifest:transform	5	24.7ms	30.2ms	+22.3%	30.2ms	6.3ms	5
web	manifest:stage	10	3.6ms	2.6ms	-27.8%	2.6ms	0.4ms	10
web	manifest:transform	5	0.5ms	0.5ms	0.0%	0.5ms	0.1ms	5

Synthetic Rsbuild App

Rendered 2 production build benchmarks.

Benchmark	Runs	Base total	Head total	Delta	Head mean	Head p95	Speedup	Head RSS p95
complex app	3	112.59s	118.84s	+5.6%	121.81s	-	0.95x	-
complex app	3	77.44s	86.81s	+12.1%	86.29s	-	0.89x	-

Rendered 1 dev benchmark fixture from the embedded complex app.

Benchmark	Runs	Base total	Head total	Delta	Base ready	Head ready	Base routes	Head routes	Base update/HMR	Head update/HMR	Update delta	Head mean	Head p95	Speedup	Head RSS p95
complex app	3	99.43s	102.11s	+2.7%	87.45s	91.91s	2.69s	3.02s	3.27s	2.60s	-20.7%	101.85s	-	0.97x	-

Profile: ci-small+ci-large; mode: dev; iterations: 5; warmup: 1.
The uploaded benchmark artifact includes diagnostics/summary.md and diagnostics/summary.json with runner metadata, per-run timing samples, CPU/RSS samples, and plugin timing hot spots.
Workflow run